无线多址信道中的协作模型研究

在无线多址信道环境下,为了充分利用协作分集技术提高系统的传输速率和通信质量,引入了多址接入中继信道（MARC）模型。通过加入一个专门的中继节点,MARC模型中的发送节点类似操作在普通的多址信道下,从而使得现有的系统可平滑过渡到协作系统,实用性强。把MARC模型应用在直序扩频CDMA系统中,在Rayleigh信道下对其误码率进行仿真,结果表明,采用MARC模型的协作网络能获得显著的性能增益。     

一种LTE系统中的基站内切换实现方案

为了实现LTE(长期演进)系统中的基站内切换,文章从控制面和用户面信令流程的角度出发,提出了一种LTE系统中的基站内切换设计方案。通过基站内各模块的协同工作,可有效实现包含数据转发的基站内切换流程,确保切换过程中不丢包,实现平滑切换。将该方案应用于实际的测试中,进行了基站内切换的组网测试,并给出了实际的切换测试结果。     

基于软件定义网络的安全态势感知方式分析

本文首先分别详细地阐述了软件定义网络和态势感知的概念,随后又分别全面的分析了软件定义网络和态势感知的重点技术,通过对于这些技术要点的重点分析,为以后进一步深入研究网络的安全态势感知这项技术,提供了一个良好的借鉴作用.     

基于区块链的云数据匿名确定性删除方法

现有确定性删除方案忽略了用户数据与用户身份的关联性,使用户的删除行为暴露给攻击者或云服务提供商。为解决此问题,提出一种基于区块链的云数据匿名确定性删除方法。该方法改进了可链接环签名方案,使用户可以通过控制签名中的链接标记在匿名情况下实现确定性删除;同时,它利用区块链记录删除行为,使其具有不可抵赖性。理论分析和实验表明:该方法不仅能满足用户数据的确定性删除要求,而且具有匿名性可以切断用户数据与其身份的关联,从而有效避免攻击者或云服务提供商对用户行为的追踪分析。     

支持5G LAN的UPF转发模型

5GLAN功能已经成为5G网络在工业互联网应用中最重要的增强能力之一。参考传统交换机的常用组网拓扑,分析了5GLAN的组网和转发需求,研究了支持5GLAN功能的UPF转发模型,设计了UPF软件架构,并基于开源软件完成了Ethernet类型5G LAN的基本转发功能验证,为5G LAN技术研究和应用提供参考。     

On designing incentive-compatible routing and forwarding protocols in wireless ad-hoc networks

In many applications, wireless ad-hoc networks are formed by devices belonging to independent users. Therefore, a challenging problem is how to provide incentives to stimulate cooperation. In this paper, we study ad-hoc games—the routing and packet forwarding games in wireless ad-hoc networks. Unlike previous work which focuses either on routing or on forwarding, this paper investigates both routing and forwarding. We first uncover an impossibility result—there does not exist a protocol such that following the protocol to always forward others' traffic is a dominant action. Then we define a novel solution concept called cooperation-optimal protocols. We present Corsac, a cooperation-optimal protocol which consists of a routing protocol and a forwarding protocol. The routing protocol of Corsac integrates VCG with a novel cryptographic technique to address the challenge in wireless ad-hoc networks that a link’s cost (i.e., its type) is determined by two nodes together. Corsac also applies efficient cryptographic techniques to design a forwarding protocol to enforce the routing decision, such that fulfilling the routing decision is the optimal action of each node in the sense that it brings the maximum utility to the node. We evaluate our protocols using simulations. Our evaluations demonstrate that our protocols provide incentives for nodes to forward packets. Additionally, we discuss the challenging issues in designing incentive-compatible protocols in ad hoc networks. Part of this paper appeared in a conference version [49]. Sheng Zhong was supported in part by NSF grants ANI-0207399 and CNS-0524030. Yang Richard Yang was supported in part by NSF grants ANI-0207399, ANI-0238038, and CNS-0435201. This work was partly done while Sheng Zhong was at Yale University; Yanbin Liu was at University of Texas at Austin. Sheng Zhong is an assistant professor in the State University of New York at Buffalo. He received his PhD (2004) from Yale University and his ME (1999), BS (1996) from Nanjing University, China, all in computer science. His research interests include economic incentives and privacy protection, particularly incentive and privacy problems in mobile computing and data mining. Li Erran Li received his B.E. in Automatic Control from Beijing Polytechnic University in 1993, his M.E. in Pattern Recognition from the Institute of Automation, Chinese Academy of Sciences, in 1996, and his Ph.D. in Computer Science from Cornell University in 2001 where Joseph Y. Halpern was his advisor. He is presently a member of the Networking Research Center in Bell Labs. His research interests are in networking with a focus on wireless networking and mobile computing. He has served as a program committee member for several conferences including ACM MobiCom, ACM MobiHoc, IEEE INFOCOM and IEEE ICNP. He is a guest editor for JSAC special issue on Non-Cooperative Behavior in Networking. He has published over 30 papers. Yanbin Liu received her B.E. degree in Computer Science and Technology from Tsinghua University (1993), Beijing, China, in 1993, and her M.S. degree in Computer Science from the University of Texas at Austin (1998), where is a Ph.D. candidate. Since 2006, he has been with IBM TJ Watson Research Center, Hawthorne, NY. Her research interests are in real-time systems, grid computing, mobile computing, and computer networks. Yang Richard Yang received his B.E. degree in Computer Science and Technology from Tsinghua University, Beijing, China, in 1993, and his M.S. and Ph.D. degrees in Computer Science from the University of Texas at Austin in 1998 and 2001, respectively. Since 2001, he has been with the Department of Computer Science, Yale University, New Haven, CT, where currently he is an Associate Professor. His current research interests are in computer networks, mobile computing, and sensor networks. He leads the Laboratory of Networked Systems (LANS) at Yale University.     

一种基于数据平面可编程的软件定义网络报文转发验证机制

针对软件定义网络(SDN)中OpenFlow协议匹配字段固定且数量有限,数据流转发缺少有效的转发验证机制等问题,该文提出一种基于数据平面可编程的软件定义网络报文转发验证机制。通过为数据报文添加自定义密码标识,将P4转发设备加入基于OpenFlow的软件定义网络,在不影响数据流正常转发的基础上,对网络业务流精确控制和采样。控制器验证采样业务报文完整性,并针对异常报文下发流规则至OpenFlow转发设备,对恶意篡改、伪造等异常数据流进行转发控制。最后,构建基于开源BMv2的P4转发设备和基于OpenFlow的Open vSwitch转发设备的转发验证原型,并构建仿真网络进行实验。实验结果表明,该机制能够有效检测业务报文篡改、伪造等转发异常行为,与同类验证机制相比,在安全验证处理开销保持不变的情况下,能够实现更细粒度的业务流精确控制采样和更低的转发时延。

     

基于ODMRP的贪婪稳定路由协议

针对ODMRP协议在拓扑频繁变化的移动自组网中存在的不足,提出一种贪婪稳定路由协议GS-ODMRP,通过贪婪转发机制建立主路径,每条链路的备用路径基于链路保持连接时间建立,从而提高协议的鲁棒性.仿真结果表明,相比ODMRP协议,GS-ODMRP协议提高了分组传输成功率,并且降低了网络开销和传输时延.     

A venues‐aware message routing scheme for delay‐tolerant networks

With their proliferation and increasing capabilities, mobile devices with local wireless interfaces can be organized into delay‐tolerant networks (DTNs) that exploit communication opportunities arising out of the movement of their users. As the mobile devices are usually carried by people, these DTNs can also be viewed as social networks. Unfortunately, most existing routing algorithms for DTNs rely on relatively simple mobility models that rarely consider these social network characteristics, and therefore, the mobility models in these algorithms cannot accurately describe users’ real mobility traces. In this paper, we propose two predict and spread (PreS) message routing algorithms for DTNs. We employ an adapted Markov chain to model a node's mobility pattern and capture its social characteristics. A comparison with state‐of‐the‐art algorithms demonstrates that PreS can yield better performance in terms of delivery ratio and delivery latency, and it can provide a comparable performance with the epidemic routing algorithm with lower resource consumption. Copyright © 2013 John Wiley & Sons, Ltd.     

双信号单通道红外光传输

以FPGA作为控制核心,设计了一种脉冲频率调制(PFM)与脉冲宽度调制(PWM)对信号先后调制,并用红外光来进行同时传输的装置。发送端通过FPGA自带的高速AD对音频信号采样,通过PFM与PWM来实现音频信号的调制,接收端FPGA对光脉冲进行解调输出。设计中发射电路与接收电路完全采用分离元件进行构建,具有成本低、功耗小、传输效率高等优点。通过对设计结果的分析可以得到在12 m内,1～10 kHz的音频信号和数字信号能够在一个通道里进行无失真的实时传输。传输信号经过中继站实现信号向不同方向转发的功能。同时中继站的功耗为0.08 W,满足节能的要求。